//==============================================================================
//===	Copyright (C) 2001-2008 Food and Agriculture Organization of the
//===	United Nations (FAO-UN), United Nations World Food Programme (WFP)
//===	and United Nations Environment Programme (UNEP)
//===
//===	This program is free software; you can redistribute it and/or modify
//===	it under the terms of the GNU General Public License as published by
//===	the Free Software Foundation; either version 2 of the License, or (at
//===	your option) any later version.
//===
//===	This program is distributed in the hope that it will be useful, but
//===	WITHOUT ANY WARRANTY; without even the implied warranty of
//===	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
//===	General Public License for more details.
//===
//===	You should have received a copy of the GNU General Public License
//===	along with this program; if not, write to the Free Software
//===	Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
//===
//===	Contact: Jeroen Ticheler - FAO - Viale delle Terme di Caracalla 2,
//===	Rome - Italy. email: geonetwork@osgeo.org
//==============================================================================
package org.fao.geonet.kernel.search;

import org.apache.lucene.search.BooleanClause;

/**
 * Utilities for the Lucene library.
 */
public class LuceneUtils {
	
	/**
	 * As of Lucene 1.9, the use of <code>BooleanQuery.add(Query, boolean, boolean)</code> was deprecated 
	 * and replaced by <code>BooleanQuery.add(Query, BooleanClause.Occur)</code>. This utility method 
	 * converts the old pair of booleans to the corresponding <code>BooleanClause.Occur</code> value.
	 * 
	 * @TODO throw exception if both booleans are true
	 * 
	 * @param required
	 * @param prohibited
	 * @return BooleanClause.Occur
	 */
	public static BooleanClause.Occur convertRequiredAndProhibitedToOccur(boolean required, boolean prohibited) {
		BooleanClause.Occur occur = null;
		if(required && !prohibited) {
			occur = BooleanClause.Occur.MUST;
		}
		else if(!required && !prohibited) {
			occur = BooleanClause.Occur.SHOULD;					
		}
		else if(!required && prohibited) {
			occur = BooleanClause.Occur.MUST_NOT;					
		}
		return occur;
	}

}
